N = int(input())
S = input()

i = 0
while i < N:
    if S[i] == 'n':
        i += 1
    elif S[i] == 'w':
        if i == N - 1 or S[i+1] not in ['a', 'o' ,'?']:
            print('No')
            exit()
        else:
            i += 2
    elif S[i] == '?':
        if i != N - 1 and S[i+1] in ['a', 'o']:
            i += 2
        else:
            i += 1
    else:
        print('No')
        exit()
print('Yes')